Soil pH in Vermilion, LA: Lime or Sulfur?
Typical topsoil pH in Vermilion, LA
Typical topsoil in Vermilion, LA is pH 6.15, already right for vegetable garden (6-7). Test before adding anything.
What Vermilion needs, by plant
- Already in range: lawn (cool-season grass), vegetable garden, strawberries, roses, pink hydrangeas.
- Just outside, test first: tomatoes (off by 0), potatoes (off by 0.2), azaleas and rhododendrons (off by 0.2).
- Sulfur: blueberries 4.1 lb/100 sq ft over 3 applications; blue hydrangeas 3.1 lb/100 sq ft over 2 applications.
What to do next
If your test lands near 6.15, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.
How mixed the soil is
Of the 633,345 surveyed acres in Vermilion, LA, 58% are moderately acidic (5.5-6.5), 29% are near neutral (6.5-7.3), 8% are strongly acidic (below 5.5), 5% are alkaline (above 7.3). Mapped soils run from pH 4.3 to 8.2, a spread of 3.9 units across 69 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.
Clay, organic matter and rates
Topsoil here averages 46.1% clay and 5.34% organic matter, which this site treats as clay. At 5.34% organic matter the soil buffers like a heavier one, which pushes it into the clay bracket. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 5% of mapped components carry free carbonate (lime already in the ground).
Vermilion against the rest of Louisiana
pH 6.15 is 0.61 above the Louisiana median of 5.54. 43 of 64 Louisiana counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.
Closest in pH within the state: Madison (5.82), East Carroll (6.01), Red River (6.04), Concordia (6.11), Cameron (6.16), St. Landry (6.16), Lafourche (6.28), St. Martin (6.33).
The range in Louisiana runs from Allen at 4.88 to St. Bernard at 7; Vermilion sits 60% of the way up.